1. Field of the Invention
The present disclosure relates to an Organic Light Emitting Display (OLED) device and, more particularly, to an organic light emitting display device including a sound generating apparatus configured to directly vibrate an organic light emitting display panel to generate sound.
2. Description of the Prior Art
With the development of various portable electronic devices, such as mobile communication terminals and notebook computers, there has been an increased interest in developing flat panel display devices applicable thereto.
Such flat panel display devices include a Liquid Crystal Display Device, a Plasma Display Panel, a Field Emission Display Device, a Light Emitting Diode Display Device, and an Organic Light Emitting Diode Display Device.
Among these display devices, the Liquid Crystal Display (LCD) device includes: an array substrate including a thin film transistor; an upper substrate including a color filter and/or a black matrix; and a liquid crystal material layer formed therebetween, wherein an alignment state of the liquid crystal layer is controlled according to an electric field applied between opposite electrodes of a pixel area, and thereby the transmittance of light is adjusted to display an image.
In a display panel of such a liquid crystal display device, an Active Area (AA) configured to provide an image to a user and a Non-active Area (NA), which is a peripheral area of the Active Area (AA), are defined. The display panel is usually manufactured by attaching a first substrate, which is an array substrate having a thin film transistor formed therein to define a pixel area, and a second substrate, which is an upper substrate having a black matrix and/or color filter layer formed thereon, to each other.
The array substrate or first substrate, on which a thin film transistor is formed, includes a plurality of gate lines GS extending in a first direction and a plurality of data lines DL extending in a second direction perpendicular to the first direction, and one pixel area P is defined by each gate line and each data line. One or more thin film transistors are formed in one pixel area P, and gate and source electrodes of each thin film transistor may be connected to a gate line and a data line, respectively.
Among the above-mentioned display devices, the liquid crystal display device does not have its own light-emitting element and thus needs a separate light source. Therefore, the liquid crystal display device has a back-light unit having a light source, such as an LED, which is arranged at the rear surface thereof and irradiates a light toward a front surface of the liquid crystal panel thereof, thereby projecting a recognizable image.
Meanwhile, the organic light emitting display device has recently been in the spotlight as a display device, because the organic light emitting display device has a fast response rate, high light emitting efficiency, high luminance and a wide viewing angle, which are advantages associated with the organic light emitting display device, because the Organic Light Emitting Diode (OLED) self-emitting element.
Therefore, the organic light emitting display device does not require a back-light, which is used in a liquid crystal display device using a non-light-emitting element. Thus, the OLED can be made lighter and thinner than a liquid crystal display devices. Further, the organic light emitting display device has an excellent viewing angle and an excellent contrast ratio and is advantageous in view of the power consumption, in comparison with the liquid crystal display device. Moreover, the organic light emitting display device can be driven by a low voltage direct current, has a rapid response speed, and includes solid internal components. Therefore, the organic light emitting display device is not damages by an external impact, can be used in a wide temperature range, and requires a low manufacturing cost.
In displaying an image, the organic light emitting display device uses a top emission scheme or a bottom emission scheme according to the structure of the organic light emitting display device. In the bottom emission scheme, a visible light generated in an organic light emitting layer is displayed toward the lower side of a substrate having a transistor disposed thereon. In contrast, in the top emission scheme, the visible light generated in the organic light emitting layer is displayed toward the upper side of the substrate having a transistor disposed thereon.
In such an organic light emitting display device, sub-pixels including organic light emitting diodes are arranged in a matrix form and brightness of selected sub-pixels by a scan signal, which is controlled based on the gradation of the data.
Meanwhile, a set apparatus or finished product including such a display device as described above may include, for example, a television (TV), a computer monitor, and an advertising panel.
Such a display device or set apparatus includes a sound output device, such as a speaker, for generating and outputting sound relating to an image It is general that a company which manufactures a display device, such as a liquid crystal display device or an organic light emitting diode display device, manufactures only a display panel or display device, while another company which manufactures a speaker, assembles the speaker with the manufactured display device, so as to finally complete a set apparatus capable of outputting an image and sound. FIG. 1 is a schematic plan view of a speaker included in a conventional display device. As shown in FIG. 1, the conventional display device 1 or set apparatus includes a speaker 2 disposed at a rear or lower part of a display panel thereof.
In this structure, the sound generated by the speaker 2 does not progress toward a viewer, who is viewing an image from the front side of the display device 1, but progresses toward the rear side or the underside of the display panel. Therefore, the sound may disturb the viewer's immersive experience.
Further, when the sound generated from the speaker 2 progresses toward the rear side or underside of the display panel, the sound quality may be degraded due to interference with sound reflected by a wall or floor.
Also, the sound generated by a speaker included in the conventional display device is not oriented toward a viewer of the display device and may thus undergo diffraction, which degrades sound localization. Moreover, in configuring a set apparatus, such as a TV, a speaker may occupy a predetermined space, which imposes a restriction on the design and spatial arrangement of the set apparatus.
Therefore, there has been an increasing interest in developing technology which can improve the quality of sound output from a display device and prevent disturbance of the viewer's immersive experience.